This chapter is from the book

The Only Layer Mask “Gotcha”

THERE’S ONE LITTLE DIFFERENCE YOU NEED TO KNOW ABOUT REGULAR LAYER MASKS BEFORE MOVING ON

Okay, you got me. I lied earlier. Really, it was just a tiny lie. I said earlier that there was no difference between the
layer mask that was added automatically with the adjustment layer and the layer mask that you add to a regular layer. Well,
that’s not totally true. There is a very small difference. When we added the adjustment layers, all you had to do was click
anywhere on the adjustment layer to edit its layer mask. Well, with a regular layer mask, it actually matters where you click
on the layer.

Step 1: Open Two Photos to Blend Together

First, go ahead and open two photos. They could be of anything, but I take any chance I can to show off my two sons, Ryan
and Justin. Select all of one of the photos (press Command-A [PC: Ctrl-A]), then copy-and-paste it into the other one by pressing
Command-C (PC: Ctrl-C), switching to the other photo, and pressing Command-V (PC: Ctrl-V), so there are now two layers in
one document. With the top layer active, click on the Add Layer Mask icon at the bottom of the Layers panel to add a layer
mask to the top layer.

Step 2: Notice the Two Thumbnails that Appear in the Layers Panel on the Layer with a Mask

Take a closer look at the top layer (the one with the mask). Notice how there are two thumbnails on that layer? One is the
actual layer thumbnail that gives you a little preview of what is on that layer. The other is the layer mask itself.

Step 3: Click on the Layer Thumbnail to Select it

Click once on the actual layer thumbnail to select it. And I mean click on the thumbnail itself, not the highlighted area
around it. If you look closely, you’ll see a small black outline around the corners of the thumbnail. That’s Photoshop’s way
of telling you that the layer is selected and ready to edit. If you were to get the Brush tool (B) and paint with black at
this point, you’d be painting with black on the photo itself and you would see the black brush strokes everywhere you paint.

Step 4: Click Once on the Layer Mask Thumbnail to Select it

This time, click once on the layer mask thumbnail to select it. Look closely again and you’ll see that black outline now appears
around the corners of the layer mask, not the layer thumbnail. Now paint with a black brush on the layer mask. Wherever you
paint with black, you’ll start hiding the photo on that layer and revealing the layer underneath it, as you see here.

Step 5: It Makes a Difference what Thumbnail You Select and Paint on

See how it makes a difference when it comes to what thumbnail you select in the Layers panel? That’s why it’s important to
know that if you want to do something to the layer mask, you’ve got to actually click on that layer mask thumbnail. If you
want to do something to the actual image or what you see on that layer, then click on the layer thumbnail. So, when you work
with layer masks, if things aren’t showing up like you thought they should, take a look over at the Layers panel and see which
thumbnail is selected. Ninety percent of the time, that’s the cause. Okay, now we can move on. See? I told you it was only
a small lie.